Dr Albert G.J. Tacon obtained his PhD in fish nutrition at
University College (University of Wales), and went on to
lecture and at the University of Aston in Birmingham and
at the Institute of Aquaculture in Stirling. In 1984 he
joined FAO as an aquafeed and nutrition expert. In 1999
he moved to Hawaii to become Director of the Aquatic
Feeds and Nutrition Program at the Oceanic Institute.
Since then Albert was has been working as Technical
Director, Aquatic Farms Ltd., Hawaiâ&#x20AC;&#x2122;i, as an independent
consultant in aquaculture and aquaculture nutrition and
feed. He has more than 200 scientific publications and
one patent. He currently serves as Scientific Advisor on
Aquatic Resources to the International Foundation for
Science, Sweden, is Editor in Chief of Reviews in
Aquaculture, serves on the editorial board of
Aquaculture Nutrition and Aquaculture Research, and is
on the board of directors of the charity Aquaculture
without Frontiers (AwF).

Interview
with Dr. Albert G. J. Tacon
AQUAFEED.COM It seems almost
everyone who has ever written a paper
or made a presentation on aquaculture
feed has your name as a citation
somewhere, often in association with
statistics. In your many years of collecting
data on the industry, what do you see as
the most significant change?
AGJT I would say the most significant
change has been the intensification of
the farming systems used for the

production of freshwater fish species and
marine shrimp, and the increased use of
extruded fish feeds for freshwater fish,
salmonids, and to a lesser extent marine
fish species raised in open cage culture
systems.

AQUAFEED.COM There is a major trend
away from fishmeal inclusion in
aquafeeds. What alternative protein
sources do you believe hold most

promise in terms of nutrition, availability
and sustainability?
AGJT The largest source of animal
protein available for use in aquafeeds are
those derived from the terrestrial
livestock production sector, including
poultry by-product meals, feather meals,
blood meals, porcine meals, and
ruminant by-product meals. Provided
that the meals are produced from
healthy food-grade livestock, I see no

6
limitation to their use and availability.
Apart from these products, there are the
plant protein meals derived from
oilseeds (such as soya, canola, and
cottonseed), cereal grains (such corn
gluten meals, corn protein concentrates,
high-protein dried distillers grains and
solubles, wheat gluten meals, rice
protein concentrate), and other plant
protein concentrates (such as pea
protein concentrates, potato protein
concentrate, lupin protein meals).
Probably the most exciting and promising
protein sources are those derived from
the mass production of microorganisms
from low-cost agricultural waste streams
and substrates, including bacterial SCP,
Yeast SCP, and algal SCP. Other widely
talked about protein sources such as
animal invertebrate meals (such as
terrestrial insect meals and marine
polychaete meals) are also of growing
interest, but until production of these
products reaches into the thousand of
tonnes range their use will be limited.

AQUAFEED.COM Disease has
decimated shrimp farming throughout its
history; Acute Hepatopancreatic Necrosis
Disease (AHPND), or Early Mortality
Syndrome (EMS) as it's more popularly
known, comes immediately to mind.
Where do feeds fit in, in terms of risk?
AGJT I feel that feeds pose a serious risk
in terms of potential disease introduction, and in particular from the
current almost universal use of nonsterilized live food organisms during the
broodstock and hatchery/nursery
production cycle (including the use of live
marine polychaetes worms, Artemia
nauplii and biomass) process, and to a
lesser extent from the use of
inadequately processed shrimp head

meals (derived from cultured shrimp)
within grow-out feeds. The whole of the
area of feed biosecurity has not been on
the radar screen of most shrimp farmers
and should be!

AQUAFEED.COM Aren't there already a
slew of regulations in place governing the
safe production of aquafeed?

AQUAFEED.COM In our interview with
Dr. Dean Akiyama (Aquafeed Vol.8 Issue
3 2016), he said the major constraints on
shrimp feed production are the shrimp
farms and management. Would you
agree?

AGJT No, I believe there is much more
that needs to be done to ensure that the
farmer receives a quality feed which
meets all the dietary nutrient
requirements of the target species for
optimum growth and health. There are
currently some major aquaculture and
aquafeed producers where no
government regulations exist for the
manufacture of compound aquafeeds.
Clearly this must be remedied for the
benefit of the farmer and the consumer
of the farmed fish and shrimp.

AQUAFEED.COM What steps can be
taken along the supply chain to ensure
aquafeeds do not introduce pathogens to
the shrimp farm?
AGJT I see two possible approaches,
first, that individual potential
contaminated marine feed ingredients or
live food organisms be sold as either
being pathogen free or sterilized/
pasteurized prior to shipment, and
secondly, that feeds be sterilized/
pasteurized during the feed
manufacturing process, either by
extrusion processing, or by gamma
irradiation. Moreover, the re-feeding of
the same species back to the same
species (intra-species recycling, ie
feeding shrimp to shrimp) should be
prohibited by law so as to prevent

AGJT Yes I would agree. In my opinion
the shrimp industry must follow the
example of the livestock sector in terms
of biosecurity, and move away from the
use of open pond-based culture systems
to the development of closed fully
biosecure culture systems where
pathogens can be excluded and the
rearing environment controlled so as to
minimize shrimp stress and optimize
water quality. Moreover, the success or
not of a feed is dependent upon the
management of the feed on the farm by
the farmer; in this regard feed companies
and government have a critical role to
play in assisting the farmer; the bulk of
shrimp production within most Asian
countries still being conducted by smallscale farmers within limited financial
resources and training.

AQUAFEED.COM Do you see a big move
from pelleted to extruded shrimp feed?
Any other production trends?

AGJT Yes, I believe the shrimp sector will
eventually follow the finfish sector
concerning the increased use of extruded
shrimp feeds for both improved
nutritional characteristics and shrimp
performance, increased feed biosecurity,

7
and more importantly to reduce feed
costs per unit of shrimp production.
Other production trends will include the
development of improved application
technologies for the top-dressing of
feeds with heat sensitive feed additives,
including feed attractants, enzymes,
vitamins, pigments, and probiotics.

AQUAFEED.COM We hear all the time
that aquaculture holds the solution to
feeding the world's exploding population.
How important is fish and seafood to
human nutrition?
AGJT Very important. On a global basis
fish and seafood products constitute the
third major source of dietary protein
consumed by humans after cereals and
milk, representing 6.5% of total protein
supply or 16.4% of total animal protein
supply. However, it is also apparent that

fish supply through capture fisheries has
not been able to keep up with population
growth over the past two decades, and
that aquaculture is the only real hope to
increase production and global market
availability in the long-term. Moreover,
it is also clear that fish and seafood plays
a greater role in the nutrition of lowincome countries within the African
continent (primarily derived from
capture fisheries) and within the Asian
region in general (primarily derived from
aquaculture). Within the Asian region,
fish and seafood products were the third
major source of dietary protein consumed after cereals and vegetables,
representing 7.5% of total protein supply
(21.9% of total animal protein supply),
1.7% of total fat supply, and 1.3% of total
calorie supply.

AQUAFEED.COM Finally, what is the
one thing you'd like to see happen in
aquaculture before you retire?
AGJT I have no intention of retiring (as
long as my health holds out), but if I had
to pick something it would be that the
aquaculture industry realize the real
value of the product they are producing,
not only in terms of its content of DHA or
EPA, but also in terms of all the other
essential nutrients present within fish
and seafood products (in marked
contrast to most terrestrial animal
livestock produce), including high quality
digestible animal protein, omega-3 fatty
acids, and much needed essential
vitamins and minerals â&#x20AC;&#x201C; a complete much
needed superfood!

The global aquaculture
industry must grow rapidly
to meet the increasing
needs of quality seafood as
by 2030 more than 60 per
cent of this should come
from farm based production
systems. There is all round
consensus that this needs to
come from sustainable
aquaculture practices. The
scope of sustainable
practices trickles down to
traceability, quality control
and food safety at the
feedmill.

The main objective of extrusion
processing of aquafeeds is to produce
feed with desirable characteristics to
meet the specific needs of the wide
variety of farmed aquatic species
depending on their farming practices â&#x20AC;&#x201C;
extensive/ intensive, indoor/ outdoor,
and their various growing stages. Some
of the key physical characteristics of the
feed for important consideration are pellet size (diameter & length), floating/
sinking (bulk density), pellet durability,
water stability and its ability to uptake
fat coatings. Stringent quality control at
various stages of extrusion processing
will help to ensure that the aquafeed
produced meet the highest standards.
There are several inline and online tools
now available which makes this job much
easier and helps to integrate this into the
production system with minimal human
intervention.
To begin it is essential to understand the
benefits of quality control of the
production system with lab confirmation
of the results. As aquatic feed volumes
increase from multiple production units
or simply increased capacity of individual
production machines, production of 100
tons per hour at a single facility or more
is going to be more common. The actual
time from start to finish producing an
aquatic feed is about 1 hour including

mixing, grinding, conveying, extruding,
drying coating and cooling. Want to wait
until the end of the process to find out
you are not in product specifications? It
is considered important to assess the
product as it progresses through the
system with checks along the way to
insure product quality is achieved greatly
reducing rework and returns and
reducing cost of continued processing of
out of spec product.
Quality control starts in the raw material
receiving area, lab tests to verify the
ingredients received are up to specifications defined to suppliers. In many cases
a NIR system is used for these tests to
verify the ingredient composition.
Assuming all is good at this point the
process starts. An initial quality test
could be a NIR inline system to verify the
formulation post grinding and mixing just
prior to the extruder includes all
ingredients as specified avoiding running
a formula which is lacking. Additional in
line systems offering visual determination to confirm the mix is ground. There
are additional devices to determine
grinding screen quality, no holes in the
screen, due to amp load variations
detected on the main drive of the
grinder.
The process continues and the material
arrives at the extruder, an explainable

9
process but one that preforms many
functions in a matter of seconds. The
size, durability, density, cell structure,
shape, appearance all happen so fast it is
hard to visualize. Computer controls can
greatly assist in these events all occurring
at the same time. To start the use of loss
in weight dry ingredient feeding insure
the proper mix of the added liquids to
the dry mix with the use of liquid flow
meters and computer controls. Pellet
size and density of the pellets are
important due to the varieties of fish and
their life stages. Size is control by the die
opening and knife speed, can be
monitored by a camera and measurements can occur to determine the
correct specifications or the operator
monitors and adjusts manually, with the
latter being quite normal. Automatic
Density Control has been developed due
to availability of an accurate inline device
where density is checked post extruder
but before the dryer to insure the correct
gram per liter density desired before
expending energy removing water from
an out of spec product. Tests occur about
every 45 seconds. The Bulk Density
System(BDSâ&#x201E;˘) takes a sample mid steam
checks the density and informs the
computer control the results. Automatic
modulation of the screw speed and or

flow restrictor behind the die achieve the
needed changes to adjust the density
into the range desired. Tested again and
verification continues. The same unit can
also detect moisture and thus additional
control on water management into and
out of the dryer. You do wish to sell
water and or at least have the maximum
level stated on the bags achieved?
Durability, cell structure and possible oil
up take qualities can be monitored with a

Fig 2: How the Automatic Density System Functions.

constant indication of specific mechanical energy (SME) inputs. SME is proven
to be a good indication of the energy
input for a product and it relates to
product quality when studied based on a
formulation used. In high oil content
aquatic feeds this is essential data to be
sure the cell structure is such that the oil
will be absorbed and stay in the pellet
until delivered to the fish. The other
option is to wait to hear from the
farmers which usually is not good news.

10

Fig 3: Computer Screen with SME Indication, as seen in the dry feed Totals box gives Physical Characteristic Verification, relates to durability and
cell structure of a formulation. Controls allow for predictably of results.

In high oil feeds, oil is absorbed
differently in pellets of varying
moisture levels.
The Back-Pressure Valve, BPV, is
designed to be adjusted while running
allowing the cooking effect or energy
inputs to be controlled without stopping
the extruder to adjust the barrel
configuration. Great reduction in out of
spec product continuing through the
process.

Automatic Control packages can also
include data logging coupled with visual
and photographic devices to create
reports for files and future reference and
traceability.
Mentioned earlier is the BDSâ&#x201E;˘ In line
system also measures moisture, a critical
ingredient and one that is monitored for
obviously shelf life quality characteristics.
In the aquatic arena, moisture variations
in the pellets do effect profitability as
well as downstream potential coatings.
In high oil feeds oil is absorbed differently in pellets of varying moisture levels.

Dryers also utilizing in line system can
achieve correct post dryer moisture
levels at or near a 0.5% moisture
variance. Quite accurate for maximizing
water in the feed as well as the needed
quality control for further downstream
processes. These devices and others also
allow for energy and exhaust air humidity
readings to monitor and adjust the
process for climatic conditions which
vary from day to night as well as the
seasons throughout the year. Advantages can also be gained in this area
when changing from one product
characteristic to another.

11

Fig 4: Computer controls in conjunction with Source Technology allows for Data Logging
including photos and Data on products produced.

Current real world quality control starts
with production systems that allow for
product correction via computer controls
coupled with In -Line systems to take
critical measurements for rapid process
corrections. This technology greatly
assists in improved operation efficiency,
achieving consistent product quality,
minimizing out of spec product production, which is vital in modern day large
production systems where 15 to 20MT/
hr of feed is being produced per
extrusion system. Plant efficiencies show
that waiting to learn the results of
production by manual testing at the end
of the process is not cost effective and
also results in loss of production time as
well as expensive ingredients, greatly
impacting the profitability of the feedmill
at the end of the year. Quality control is
now incorporated into the production
process, greatly improving the desired
final product characteristic results at

Plant efficiencies show
that waiting to learn the
results of production
by manual testing
at the end of the process
is not cost effective
and also results
in loss of production
time as well as
expensive ingredients,
greatly impacting the
profitability of the feedmill
at the end of the year.

Yes !

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In the most simple of
terms, the transformation
of raw materials into a
product, involves the input
of energy. The means by

which the energy is
imparted, is defined by the
physical design of the
equipment and operational
parameters of the process.
The type of energy has a
direct influence upon the
product characteristics, for
example, color, texture and
flavor.
Let us consider a generic cooking
process, shown schematically in Figure 1.
There are three mechanisms for energy
transfer. These are:

Figure 1 – The Generic Cooking Process
In large-scale extrusion, conduction energy is relatively insignificant – as size of the extruder
increases, the reduced surface area to volume ratio in the barrel reduces heat transfer from
the barrel wall. Some of the energy in extrusion is commonly added through steam, especially
via the Preconditioner, so Convection Energy can be significant. But the nature of the process
means that a lot of the heating during extrusion is due to Mechanical Energy.

indirect heat transfer – conduction
from the vessel wall)

SME (Specific Mechanical Energy)
and Feed Extrusion
This mechanical energy input, often
specified as Specific Mechanical Energy
(SME) is critical to the quality characteristics of the extruded feed. The stresses
developed in the material (“Shear

Stress”) not only convey the product
along the barrel, but cause mixing, and
under the correct conditions, can break
down Starches and re-align proteins and
develop structure within the dough or
melt. But intense shear stress can also
cause breakdown at a molecular level, as
will be discussed later.
The shear stress applied to the product is
dissipated through the viscous fluid
movement of the melt (“Viscous

14

This temperature increase directly drives
the cooking reactions that occur. But
SME also affects the feed being manufactured at the molecular level. Figure 2
shows measured effect of SME on Mean
Molecular Weight of the starch fraction
in an extrusion operation. The shear
generated in the process breaks down
molecules – the higher the SME, the
smaller is the average molecule size.
Break-down of proteins results in the
generation of peptides and changes to
fatty acids. When starches are broken
down, dextrins (long-chain sugars) are
produced.

MMW (x106 g mol -1)

Dissipation”) leading to an increase in the
temperature of the material. The bulk
effect of SME is noted as a temperature
rise (additional to temperature rise due
to added steam).

(1)
Flavor and nutritional profile –
changed amino acids due to break-down
of proteins, bitter notes from peptides,
sweeter taste from dextrins. The
Digestibility of certain components can
be enhanced (for certain species).
(2)
Pellet durability – sufficient
“cook” is essential to the development of
Structure via the starches (present in
very limited quantities in many aquafeeds) and any functional proteins.
However, excessive breakdown of the
molecules destroys binding. Therefore
with respect to pellet durability, there
must be sufficient SME to promote the
correct Degree of Cook, but too much
SME will weaken the pellet structure.
(3)
Water stability - The formation
of dextrins lead to a reduction in the gel
forming capability of any starch present;

WAI (%)

This break-down of molecules affects
product characteristics in a number of
ways:

hence, a reduction in the Water
Absorption Index (WAI). WAI is often
used as a means of quantifying the water
stability of a product. Some data for an
extrusion process is shown in Figure 3.
Note that the most significant changes to
WAI occur within the same range of

SMEs that cause a major change in
molecular weight (Figure 2).
Smaller molecules also tend to be more
water-soluble, the Water Solubility of the
product increases (as measured by the
Water Solubility Index WSI). The data for

the test samples is presented in Figure 4.
An increase in water solubility in
aquafeed corresponds to a reduction in
water stability.
(4)

Digestibility – Change in level of

Figure 5: Example of the effect of SME on digestibility (starch-based
cat food).

“cook” and in the molecular weight also
affects digestibility. Typically, uncooked
material has low digestibility. As level of
cook increases, digestibility increases –
up to a maximum. However, at higher
SME levels, digestibility again decreases –

over-sheared product is not readily
absorbed by the animal. By way of
example, Figure 5 shows the effect of
SME on digestibility of an extruded
starched-based product (in this case in
cats).

16
How is SME Measured/
Calculated?

Table 1 – Specific Energy Inputs for the manufacture of Aquatic Feeds

Remember that SME is about the
mechanical energy going into the
product, not Total Energy – it is
important to subtract the No-Load
Energy.

If the extruder is instrumented to provide
a direct measure of Screw Torque, then
note the torque when no product is
passing through, and Net Power Input is
given by:
Pnet = 2 π (τ – τ0) N / 60000

If a torque measurement is not available,
power can be calculated from amps
drawn by the drive motor.
For AC drives the Net Power Input (kW)
can be estimated via:

Specific Convective Energy, SCE

0.040 to 0.060 kWhr/kg

Specific Thermal Energy, STE

-0.002 to 0.007 kWhr/kg

Specific Mechanical Energy, SME

0.025 to 0.045 kWhr/kg

Total Specific Energy, TSE

0.063 to 0.112 kWhr/kg

Some Guidelines for SME in
Aquafeed Extrusion
A very broad range of aquatic feeds, with
vastly different characteristics (both
floating and sinking) for a large number
of species are prepared via extrusion
cooking using a diverse raw material
base. It is therefore impossible to define
a single target value for the magnitude of
the SME (or any of the other energy
inputs). A typical range for the Specific
Energy Inputs can be presented, however
(see Table 1 above)

The authors are presenting short courses on “Aquafeed Extrusion Technology”
and “Drying Technology” at Centre for Feed Technology, FôrTek, Norway,
In April 2017. Also an Extrusion Course in Thailand in July 2017
Details: www.fie.com.au/events

(kW)
Contact:

The SME is then readily calculated as:
SME = Pnet / MTotal

Gordon Young,
Food Industry Engineering,
Australia

(kWhr/kg)

where,
MTotal = Total Throughput Rate (kg/hr).
Note: MTotal is the Total Melt Flow through
the extruder – not after drying – and is the
flow rate of powder, water, steam, oil and
any other additives.

E: gyoung@fie.com.au
Gordon Young

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18

How to
control the
density
of fish feed
By Knut Szemjonneck, Key Account Manager Food/Feed, TEWS Elektronik, Germany
When fish feed is put into water, it
should act in accordance with the
feeding behavior of the respective fish.
This means that it should either float on
the surface or sink to the bottom.
These characteristics largely depend on
the fish feed’s density, which in turn
defines the different types of fish feed:
• Feed that floats on the surface of the
water
• Feed that sinks slowly
• Feed that sinks and is water resistant
• Feed that sinks and is extremely water
resistant
Consequently, the density of the fish

flakes, granules, pellets or chips is an
important aspect for the quality of the
product.
The moisture content of the feed is also
an important parameter for the quality
of the product throughout the production process. Both a high and a low
moisture content often lead to loss of
quality and can complicate further
processing or even prevent it entirely. An
ideal moisture content leads to a longer
shelf life and prevents the onset of
rotting.
Regular checks of the moisture and
density are therefore necessary to
produce high-quality fish feed. The

common method of quality control is
through laboratory measurements.
Operators in the fish feed process are
used to manually taking samples from
production and analyzing the moisture
and density content in a laboratory. This
provides the respective moisture and
density values that can, depending on
the method, take between 5 minutes and
a few hours to obtain. Sample taking is
both time-consuming and laborintensive, and the measured values are
generally available too late to be able to
control the production process adequately.
TEWS Elektronik has developed a
measurement technique with which the

19

The MW 4260/70 enables the continuous in-line measurement in
processing lines. Up to 3,500 measurements per second are
possible.

moisture content as well as the density
of the fish feed can be continuously
measured during the production process.
With the help of bypass sensors that are
integrated into the process, the values
are measured and visualized reliably and
accurately in a matter of seconds. A quick
and targeted intervention in the
production process is thus possible.
Improved control of the production
processes leads to energy savings as well
as less wastage and better quality of fish
feed. In short, moisture and density
measurements during the process
increase the efficiency of the entire
production chain.
The patented measuring method is based
on microwave resonance technology. As
soon as the material passes through the
field of the microwave sensor, its
resonance properties change depending
on the water content. A single configuration of the systems is all that’s needed
for it to work continuously and reliably.
The special unique feature of this
technology is the independence of color,

density, grain size or
surface influences of
the product being
measured. Contrary
to the so-called nearinfrared procedure,
which measures the
moisture content only
on the surface, the
microwave measurement equipment also
determines the core
moisture in the inside
of the product, for
example in pellets or
granules.

The Microwave Resonance
Method
Water molecules are among the smallest
molecules that are positively and
negatively charged. The moisture sensor
generates a low-energy electro-magnetic
field, which interacts with these water
molecules inside the product sample.
Since the microwave field penetrates a
few centimeters into the sample, water is
not only detected at the surface but also
in the product’s core.

referred to as the dual parameter
method.
A moisture value is then calculated on
the basis of the resonance parameters.
For every product, the moisture meter is
calibrated with the aid of a laboratory
method (e.g. LOD method or Karl Fischer
Titration), so that the product’s moisture
content can be displayed, stored or
processed as a percentage value.
The microwave resonance method can
also be used to measure bulk density,
sample mass or a sample’s weight per
area.

TEWS Elektronik has been developing and
manufacturing its patented microwave
moisture and density measurement
systems, which are used for process
control and laboratory QA in the feed
industry, for over 30 years. Based in
Hamburg, Germany, the company is also
active in the USA, with its local subsidiary
TEWS of America, and has established
service points in Hong Kong and Bangkok.

The product sample reduces the
propagation speed of the microwave
field, and the water molecules in the
sample perpetually align to the electromagnetic field, thus depriving it of
energy. The moisture meter continuously
measures these two effects, which are

in Indonesia, Thailand,
Vietnam and India. Although
the causative agent is not yet
clearly identified, WFS is
easily diagnosed by the
presence of white strings in
the surface of the water and
edges of the pond. Affected
shrimp exhibit a white
hepatopancreas and gut,
which results in mortality and
persisting stunted growth.
The present series of field
trials in collaboration with
shrimp producers in Malaysia
and Indonesia, aimed at
evaluating the potential role
of a health promoting feed
additive in WFS prevention
and treatment.

WFS is significantly affecting
shrimp production in Asia
In 2016, White Feces Syndrome (WFS)
has been reported to be a disease
problem affecting significantly shrimp
farmers in Indonesia, Malaysia, Thailand,
Vietnam, and India. WFS has been
reported since 2010 in Penaeus
monodon. From early times, the
development of WFS has been related to
the presence of high loads of organic
matter in the culture pond caused by
high stocking densities and high water

temperatures, resulting in higher feeding
rates. The improvement of hygiene and
biosecurity measures are helping to
reduce the severity but in some cases are
not enough to stop the condition and its
effects.
WFS is easily identified by the presence
of white strings in the surface of the
water and edges of the pond, and
affected shrimp show white hepatopancreas and gut. The disease is mostly
associated with the described initial
acute symptoms, followed by chronic
mortalities and stunted growth that will

22
heavily affect the yield of the culture.
Different potential pathogens have been
associated with the appearance of WFS,
including microsporidian parasites,
bacterial pathogens and gregarine-like
inclusions, but till date WFS could not be
induced under controlled conditions by a
specific pathogen.

The affection of the digestive system
(hepatopancreas and gut) leads to
malnutrition. After a strong WFS
outbreak, growth is never recovered to
the pre-outbreak levels, typically around
0.25g/day in South East Asian intensive
shrimp farms. Although some farm
strategies manage to restore the
macroscopic condition of the hepatopancreas and gut, growth continues to be
stunted. As a result, WFS outbreaks
cause many production cycles to fail
since farmers prefer to harvest instead of
growing WFS affected animals which
show slow growth and poor feed
conversion.

Functional feed additives to
prevent shrimp disease
Functional feeds containing gut health
promotors deliver with every meal an
adequate concentration of natural
antimicrobial activities into the digestive
system. These feeds are a key component of any strategy to prevent diseases
in aquaculture, particularly where
opportunistic bacteria are suspected to
be a major cause of mortality. However,
the success of this approach will depend
on the efficacy of the gut health
promotor. The gut modulating feed
additive ideally is heat stable and can
therefore be easily incorporated into
industrial aquafeeds and be present in
every meal from the starter feed

onwards, without requiring major
adaptations of the production protocols.
Natural feed additives combining
different action mechanisms such as
direct bactericide/bacteriostatic
properties as well as Quorum Sensing
Inhibition (QSI) properties at concentrations below MIC, are most promising to
control bacterial diseases caused by
opportunistic bacteria such as Vibrio spp.
The inclusion of such botanical feed
additive under standard industrial
conditions at the feed mill improved
survival under production conditions in a
semi-intensive shrimp farm in Panama
and Ecuador with 18 to 24% compared to
the control group during two independent production cycles (Cuellar-Anjel et
al., 2011; Valle and Coutteau, 2015). In
these production trials, the main disease
challenge at the farm consisted of White
Spot Disease (WSSV) and Vibriosis. The
gut health promotor was applied from
the first starter feed onwards and
continued throughout the entire cycle till
harvest. Loc et al. (2015) was able to
confirm the effect of a synergistic
phytobiotic product in a controlled
challenge trial with Vibrio parahaemolyticus (Early Mortality Syndrome, Acute
Hepatopancreatic Necrosis Disease, EMS/
AHPND strain) under laboratory
conditions; showing 62-107% increased
survival in shrimp that had received the
additive during 3 weeks prior to the
experimental infection, compared to
unsupplemented control groups.
Furthermore, the addition of the
phytobiotic product in the diet resulted
in consistently lower Vibrio spp counts in
the shrimp’s digestive system compared
to the control, illustrating the capability
of gut modulating additives to protect
the shrimp’s gut microbiota throughout a
Vibrio spp challenge. The inclusion of

natural products with bactericidal and
quorum quenching activities is an
important factor in current bio-security
protocols to prevent the vertical spread
of opportunistic bacterial pathogens such
as Vibrio spp, Photobacterium spp,
Flavobacterium spp, Tenacibaculum spp.
Furthermore, a healthy gut microbiota
enhances the overall health status and
immune defenses, which may explain the
positive effect of gut modulators on
reducing the impact of certain endo as
well as ectoparasites on productivity in
fish and shrimp.
The three field studies reported in this
study explored the preventive and/or
curative effect against WFS of a health
promoting, functional feed additive with
broad spectrum activity (SANACORE®
GM, Nutriad), added to the feed either at
the farm by top-dressing or at the feed
factory, or a combination of both
strategies. Field trials were executed in
close collaboration with shrimp
producers following standard operational
procedures in Malaysia and Indonesia.

Trial 1 in Malaysia
The first trial was conducted in a shrimp
farm located in the Penang region,
Northern Malaysia. The farm was
historically affected by EMS and WSSV
outbreaks, as well as WFS, usually
around day of culture (DOC) 60. The trial
followed standard operation procedures
of the farm and was run in 8 ponds in
total, 6 as treatment and 2 as control. For
the treatment ponds, SANACORE® GM
was top-coated in the farm and applied
to the ponds since the first day of culture
in all feedings until harvest. Due to
mortality and stunted growth, the
control ponds were harvested at DOC 42,

23
Table 1: final results on WFS - SANACOREÂŽ GM trial in Malaysia

DOC at Harvest

Number of
Ponds

Survival Rate
(%)

Final MBW
(g)

FCR

Total Crop Yield
(Kg/Ha)

Control

42

2

38

4

1.50

1,582

Treatment

129

6

66

30

1.33

13,696

Fig. 1: Survival rate at the end of culture (TRIAL 1)

while treatment ponds were continued
and harvested as planned at DOC 129.
Production data for final mean body
weight (MBW), survival (SR), and feed
conversion ratio (FCR) are shown in Figs 1
& 2 and Table 1. The average harvest
yield in the treatment ponds was 13.7
MT per ha, whereas the control ponds
resulted only in 1.6 MT per ha due to the
emergency harvest.
All treatment ponds were affected by
WFS at DOC 60 (control ponds were
already harvested at DOC 42). However,
the WFS outbreak was mild in severity
and the farmer was able to maintain
culture and harvest as planned, avoiding
the emergency crop. Following the WFS
outbreak, the treatment ponds recovered the average daily growth within 7 to
14 days.

Fig. 2: FCR at harvest (TRIAL 1)

Trials in Indonesia
The trials in Indonesia were conducted in
2 different farms located in the SubangKarawang regions in Northern Jakarta, an
area that is heavily affected by WSSV and
WFS. In both farms, the previous two
crops were aborted with an emergency
harvest due to stunted growth and
mortality of the shrimp caused by WFS.

Trial 2, farm 1 in Indonesia
The second farm trial aimed at evaluating
a preventive protocol for the application
of the functional feed additive through
the addition of a basal level of
SANACOREÂŽ GM via the feed, complemented during specific WFS episodes by
additional dosage via top-coating
application at the farm (Fig. 3). However,
the protocol was adapted during the trial
due to late arrival of the treatment feed

and the additive. As a result, the first
exposure to the feed additive in the
treatment group started only at DOC 20.

Fig. 3. Overview of the exposure of treatment and control ponds to the additive in reality during trial 2, compared with the initially proposed
protocol.

Fig 4: Evolution of ADG after the WFS outbreak

Fig 5: Evolution of MBW.

* indicates statistically significant differences (P< 0.05)

* indicates statistically significant differences (P< 0.05)

Furthermore, the incidence of a WFS
outbreak around days 23-26 in the
treatment ponds and its subsequent
successful curative treatment with

boosted levels of the feed additive during
one week, resulted in the decision of the
farmer to treat also the control ponds
when they exhibited WFS on DOC 28.

The final exposure of the treatment and
control ponds to the additive are
summarized in Fig. 3.

25
The application of the curative protocol
to the control ponds avoided their
flushing and maintained them in the trial.
All ponds, control and treatment,
received 7 days of boosted levels of the
feed additive as curative treatment,
followed by standard diet (control ponds)
or standard feed supplemented with
prevention dosage of the feed additive
(treatment). Recovery from WFS
happened in both control and treatment.
However, subsequent daily growth was
significantly different for treatment and
control groups. Whereas the control
group did not recover growth, the
treatment group recovered average daily

growth to acceptable levels within 20
days following the curative treatment
(Fig. 4).
During DOC 60-80 approximately, a
reduction of growth was detected in
both groups which could be ascribed to a
reduction of feeding rates in the farm
due to operational issues. Similar to the
trial in Malaysia, the harvest was
advanced to DOC 85 in control ponds due
to the stunted growth, while treatment
ponds were partially harvested on DOC
85 and finally harvested at DOC 100.
Comparing results, final survival was
improved in 10% (Fig. 6). Shrimp size of
the treatment group was increased with

25% compared to the control group at
DOC 85, and 42% at the final harvest of
treatment group at DOC 100 (Fig7 and
Fig 8). The treatment ponds yielded over
three times more biomass than the
control ponds at final harvest (Fig. 9).

Trial 3, farm 2 in Indonesia
The third trial was run as a confirmation
trial without control in the Northern
Jakarta area. The farm had suffered crop
failures during two subsequent stockings
prior to the trial caused by WFS in
combination with WSSV and other
diseases. Due to the high probability of

failure, the farmer did not accept to
maintain control ponds and decided to
run four ponds with the treatment
proposal. In this trial, the preventive
protocol was fully followed as proposed
in Fig. 3 from the arrival of the shrimp in
the grow-out ponds.
In trial 3, a first, mild outbreak of WFS
occurred rather late at DOC 62-66. No
additional curative treatment was
applied and the shrimp recovered
without subsequent stunted growth. This
promising outlook made the farmer
decide to continue the culture in all four
ponds. During DOC 83-88, a second
outbreak of WFS appeared, which
induced the farmer to harvest.
Final harvest results of both farm trials in
Indonesia are compared in Table 2. The
preventive approach using the feed
additive (trial 3) showed a very interesting performance with survival
amounting to 68% in average for the 4
ponds, despite the absence of any
curative treatments during two outbreaks of WFS, in an area where previous
crops failed repetitively. The curative
approach using the feed additive (trial 2)
showed a clear impact on survival and
productivity, with a 10% improvement of
survival at harvest despite the 15 days
longer period of culture. However,
comparison is difficult since the control
shrimp also received the curative

treatment during 7 days when WFS
outbreak occurred before DOC 30.

Conclusion
The current farm trials were performed
in “black” areas, i.e. culture areas where
previous cycles failed repetitively before
the trial. This was confirmed by the need
to execute emergency harvests on the
control ponds in two trials due to high
mortalities and / or stunted growth.
These trials demonstrated the capacity of
the functional feed additive treatment to
delay or control the severity of WFS
outbreak, and - most importantly for the
farmer - recover the shrimp growth to
normal levels following the WFS event.
The inclusion of the additive showed the

improvement of the production yield,
especially when applied as a preventive
strategy since the first day of stocking,
thanks to improved growth as well as
survival. Furthermore, the curative
treatment showed very positive effects,
even when applied only during the WFS
outbreak.

The results were achieved in different
farms and countries, were production
strategies, daily routines and farming
conditions are different. This further
confirms the broad spectrum action
radius of the feed additive and its
capability to reduce the impact of WFS
on economics of shrimp farming in SE
Asia.

FVG Select 2017 is a new event which will be organized by Victam International BV.
The event will focus on a series of high quality industry conferences and matchmaking
with colleagues and clients in the animal feed processing, grain processing,
ingredients & additives, aquafeed, petfood and biomass pelleting industries.
The event will be complemented by an industry expo for a select group of companies.
THE CONFERENCES AND DELEGATE PROFILES
Tuesday 13th June

A fee of â&#x201A;Ź95 per person (valid for two days) will be charged to each individual attending the event, both exhibitors and visitors, and includes lunch,
two coffee and tea breaks a day, the network reception and access to our matchmaking service. A separate fee will be charged for each conference.
More details can be found on our website.

THE INDUSTRY EXPO

EVENT ORGANIZERS

There will be 9m2 and 18m2 standard shell scheme booths available
during the two day event. The expo will take place in the adjoining hall to
the conference rooms and will also be the venue for all the refreshments.

Introduction
During standard aquaculture practices,
fish are affected by stresses such as being
handled, transported or vaccinated.
These stresses affect fish physiology and
immunity and can also cause minor
physical damage (Portz et al 2006). This
can then result in loss of appetite, poor
growth, deformities, infections and in the
worst case mortality. Managing stress in
fish is therefore an essential part to
create more robust animals.
Attaining robust animals throughout the
entire production cycle is an essential
part in the holistic approach to combat
diseases for all aquaculture organisms.
For fish, investing in the quality of larvae
and juveniles results in a significant
return on investment for subsequent
cage or pond farming. Nutrition and
health protocols have a large impact on
fish quality that lasts beyond the early
life stages. The third factor that affects
production and returns in pond and cage
culture is the quality of fry, as transport
to the on-growing site and stocking into
cages or ponds with less controlled
culture conditions is very stressful and
may affect the vulnerable fry. Stocking
high-quality, robust fish will in turn result

in a more reliable production and a
reduced disease risk in grow-out
facilities.

Aim and Rationale
INVE Aquaculture, through its Innovations Department and in collaboration
with recognized research institutes, is
continuously striving to bring innovative
and cost-beneficial concepts to the
market. To document the proof of
concept of innovative methods of
improving the hostâ&#x20AC;&#x2122;s defense system, a 3year joint research project with the
Laboratory of Aquaculture & Artemia
Reference Center (ARC) at Ghent
University was set up.
In a previous article (Aquafeed Vol 8 Issue
4 2016) we described the mechanism of
Heat Shock Protein induction (HSPi)
which results in having more chaperones
pro-actively produced in the animal so
that they can better cope with stressors
and thus having a spectacularly better
performance in abiotic stress tests and
bacterial challenges. A promising way to
improve the hostâ&#x20AC;&#x2122;s defense is thus by
stimulating its endogenous protective
pathways, such as increased heat shock

protein synthesis (Fig.1). And the
validation of HSPi in the model organism
Artemia and in larval shrimp culture was
demonstrated.

In this second article we cover our
research results with fish fry, showing
our approach to prepare fish for
anticipated stressful events. When fish
are exposed to stressful conditions, the
hypothalamic-pituitary-interrenal axis
(HPI) is activated and the release of
corticosteroid hormones such as cortisol
is induced and at the cellular level, fish
can respond to these stressors by an
increased synthesis of heat shock
proteins (Poltronieri et al 2007). By using
formulations of selected natural
components in the culture water of the
fish we aim to trigger the Heat Shock
Protein (HSP) chaperones in the cells of
the fish and thereby prevent protein
damage caused by oxidative stress from
challenging events such as transport and
grading, rather than attempting to
recover from an existing insult.
These treatments with compounds from
plant origin will enable higher survival
and more robust fry during and after
these stressful conditions.

29

INDUCTION OF HSP70 BY
NATURAL COMPONENTS

Fig.1: Mechanism of Heat Shock Protein 70 (HSP70) induction.

Results in Seabass (Dicentrarchus
labrax)
A variety of compounds from plant origin
were selected and tested on HSP
inducing properties. Seabass juveniles
(DAH30) were exposed for 2 hours to the
test compounds at different concentrations. After different recovery times the
production of HSP70 was detected and
quantified by Western blot analyses.
Results showed that the relative amount
of HSP70 increased in the seabass
treated with some of the tested
compounds from plant origin. Figure 2
shows the amount of HSP70 analyzed by
Western blot in seabass juveniles.
Exposure to a HSPi concentrate significantly increased HSP70 levels after 2 and

2h recovery

12h recovery

Control

2 mg/l

5 mg/l

Control

2 mg/l

5 mg/l

100%

135%

143%

100%

150%

150%

Fig.2: Western Blot results showing the amount of HSP70 proteins in seabass juveniles after 2
hours and 12 hours of recovery from a 2 hour exposure to different concentrations of a natural
HSPi compound in the culture water.

conditions much better than the control
animals (Fig.3). This could be very
beneficial in events such as transportation when fish arenâ&#x20AC;&#x2122;t fed for 2 to 3 days.

30
As described in the FAO review of Berka
(1986), the fish to be transported should
be left to starve for at least a day; fish
with full digestive tracts need more
oxygen, are more susceptible to stress,
and produce excrements which take up
much of the oxygen of the water.
However, when fish larvae are transported, their time of survival without food
should also be taken into consideration.

Fig.4: Survival of juvenile sea bream (10-15g) subjected to an air exposure stress test after being
pretreated with different concentrations of a HSPi concentrate (10-100mg/l) for 24 hours in the
culture water.

Fig.3: Survival of Seabass juveniles in a 6 day
starvation challenge trial. Seabass were pretreated for 2 hours with different concentrations of a natural HSPi concentrate (10-20 mg/
l) in the culture water before starvation challenge.

Results in Sea bream (Sparus
aurata)
Optimal doses for application and
different modes of application of natural
HSPi compounds in the culture water of
sea bream fry were determined. Trials
were carried out during the nursery stage
of sea bream, from 60 days post hatching
(dph) up to the pre-ongrowing stage
(<15g). Selected plant compounds were
applied shortly before critical moments
such as grading and transports when
stress related problems could occur.
Different mixtures of HSPi compounds
were tested for optimal stress resistance

Fig.5: Survival of juvenile sea bream (70 dph) subjected to an air exposure stress test 48 hours
after being pretreated with different HSPi compounds (P1, P2 & P5) for 2 hours in the culture
water.

improvement, as evaluated by air
exposure stress tests (Fig 4 & 5). Bath
treatments with different HSPi concentrates resulted in significantly increased
survival of the fish during air exposure
stress tests up to 3 days after treatment
without affecting overall survival or
growth. These findings were reinforced
by the relative amount of HSP70 proteins
present in the fish 24 hours after a 2 hour
bath treatment for different ages of fish,
showing a consistently higher HSP70

content (12-33%) in fish that were
pretreated with different HSPi compounds for 2 hours (Fig.6).
A 48 hours transport simulation trial in
sea bream of 160dph with different
doses of HSPi compounds and different
exposure times showed the beneficial
effect on stress resistance of the
treatments as evaluated by air exposure
stress tests (Fig 7).

31

Fig.6: Amount of HSP70 relative to control in seabream juveniles of different
ages 24 hours after a 2 hour bath treatment with a HSPi compound

Results in Tilapia
As for seabream, a transport simulation
trial was conducted for Tilapia of 40g

Fig.7: Survival of juvenile sea bream (160 dph) subjected to
air exposure for 8 minutes after a 48 hour transport simulation and different treatments with HSPi compound 1 (P1).
TR2 was exposed to 100mg/l P1 for 2 hours before
transport; TR3 was exposed to 100mg/l P1 for 3 hours before transport; TR4 was exposed to 50mg/l P1 for 48 hours
during transport.

with different doses of different HSPi
concentrates applied in the water during
transport (Fig 8). Results showed the

beneficial effect on stress resistance of
the treatments as evaluated by salinity
stress tests after transport (Fig 9).

Fig.9: Cumulative stress index of Tilapia (40g.) subjected to 45ppt salinity after a 48 hour
transport simulation with different treatments of HSPi concentrates during transport.

Conclusion
Through extensive scientific research and
development it was found that natural
HSPi components enhance the stress
resistance of fish by inducing the
production of Heat Shock Proteins. These
documented effects proved to significantly improve stress management for
different fish species in different age
groups. We showed that resistance to air
exposure during events such as grading
and vaccination procedures can be
measurably improved as also resistance
to starvation conditions and other

stresses during transport operations.
Overall the robustness of the fry was
visibly improved, which is an essential
part in the holistic approach to combat
diseases.

More information

Acknowledgements:
Part of this research was funded by the
Belgian Agency for Innovation by Science
and Technology (IWT), project number:
120404.

Macro algae, or seaweeds, play their role
in shaping the marine underwater world,
from the seashore to depths, where
there is enough light for seaweeds to
grow. Seaweeds were mainly used as a
food source by coastal communities or
used in folklore and medicinal purposes.
Seaweeds were and are still being used
as fertilizers, benefiting among others
from the rich mineral content. They are
also widely used in the food industry for
various purposes such as gelling,
thickening and stabilizing agents. More
recent screening has revealed a whole
new range of biological activities, such as
anti-bacterial, anti-viral, anti-hyperlipidemic, mucin inducing, etc.

Algae, a source of biological
treasures
Macroalgae, are divided in three
different groups: green, red and brown.
They are made up of a variable part of
carbohydrates (mainly polysaccharides),
proteins, minerals, lipids and vitamins.
Nutritional studies on marine algae
indicate that green, brown and red
seaweeds possess good nutritional
characteristics and could be used as an
alternative source of dietary fiber,
protein, vitamins and minerals
(Chojnacka et al., 2012; Raposo et al.,

2013). In addition, detailed screening of
macroalgae functions have revealed a
new range of biological activities
including anticoagulant, antiviral,
antibacterial, anti-tumoral and immunomodulatory activities. All of them could
be of relevance in nutraceutical
functional foods (Wijesekara et al.,
2011a). Cell walls of green, brown and
red macroalgae contain large amounts of
sulfated polysaccharides, named ulvans,
fucoidans and carrageenans respectively,
which can range from 4 up to 76% of
seaweed dry weight (Holdt et al., 2011).
The high content of these sulfated
polysaccharides, their unusual structure,
and their biological properties reveal
these compounds as promising
natural products for medicinal
and dietary applications
(Rioux et al., 2007;
Laurienzo et al., 2010). The
biological specificity of
these marine algal
polysaccharides stem
from the complexity of
their structure. Marine
algal polysaccharides are
branched polysaccharides,
they are composed of various
sugars (including rare sugar units
like xylose, rhamnose) and these
sugars can be sulfated, conferring them a

special reactivity. Together these
parameters show a phylogenic similarity
with polysaccharides from the animal
kingdom such as heparin, which explains
their unique biological properties.
Marine algal polysaccharidesâ&#x20AC;&#x2122; reactivity,
and biological properties, vary a lot
according to the type of sugars and
linkage they contain, their level of
sulfation and also their molecular weight.
Therefore, several marine algal polysaccharides, each with distinct biological
activities, can be found in algae. Their
specific extraction is a key to ensure a
targeted effect on animals.

34
Algae extracts to support natural
defenses
Polysaccharides can be extracted and
purified and one of these purified groups
is recognized as having immunomodulating properties. Studies evaluating the
immunological properties of algaederived polysaccharides were mainly
carried out using primary culture of
macrophage like cells lines (Chen et al.,
2008; Jaswir et al., 2011). However,
although macrophages are essential
effector cells of innate immunity,
intestinal epithelial cells are also of
interest since they express patternrecognition receptors (PRRs) that enable
them to act as dynamic sensors of
microbial environment and foreign
antigens. They are therefore active
participants in coordinating the mucosal
immunity by producing a broad range of
mediators involved in adjacent immune
cells activation (Peterson et al., 2014).

Assessing the immunomodulatory
effects of macroalgae extract in
vitro

Assessing the immunomodulatory
effects of algae extract in
aquaculture

A recent study, from Berri et al. (2016),
conducted in collaboration with INRA
(National Institute for Agronomy
Research) and published in the Journal of
Applied Phycology, demonstrated that
the sulfated polysaccharides with specific
immunomodulating properties, prepared
from the green algae Ulva armoricana
(Olmix MSPIMMUNITY), are able to activate
immune receptors of intestinal cells, and
to induce the expression of some
immune mediators (cytokines and
chemokines), thus modulating both
innate immunity (macrophages,
neutrophils) and adaptive immunity (T
and B lymphocytes). This suggests that
this extract could be used as a new
prophylactic strategy to stimulate the
immune response of animals, and thus
reinforce their natural defenses.

To evaluate the capacity to stimulate the
immune response in aquaculture,
MSPIMMUNITY in the form of an end
product named Searup was tested, on
shrimp. Stress and bacterial challenge
tests were set up in a University trial.
Stress tests were set up because this is
an often used method to estimate PL
quality in a hatchery and a challenge test
to evaluate the shrimp response to a
pathogenic bacteria which has a serious
impact on health.

Stress test
Shrimp post larvae (PL5), having tested
negative to WSSV, YHV, TSV, MBV and
AHPND by PCR method, were reared in 4
tanks of 500L each, with an average

35
stocking density of 50pcs/L until stage
PL12. Water in each rearing tank had a
salinity of 25ppt. Tanks were randomly
allotted to one of four treatments during
rearing:

At stage PL12, shrimp in each treatment
tank were allotted into twelve 30L tanks
(500pcs/tank). Each treatment received 3
different stress tests (2 levels of salinity
(10ppt and 30ppt) and formalin
(100ppm)) which were conducted with 4
replicates for each stress test. Mortalities
of PLs were recorded at 3h, 6h, 9h and
24h after exposure to salinity and
formalin stress.

24h after exposure, PLs from Searup
groups had significantly lower cumulative
mortality than the control group (P<0.05)
for all stress tests.

Figure 1. Cummulative mortality after 10ppt salinity challenge. The
best performance was obtained when Searup was administered for 5
and 7 consecutive days.

The use of Searup showed a dose
dependent increase in survival rates after
the stress tests, suggesting an increased
tolerance to stress such as during
handling, transport and stocking of growout ponds.

EMS challenge
Shrimp post larvae were reared from PL5
to PL25 in 4 tanks of 500L, with an
average density of 50pcs/L. All PLs tested
negative to WSSV, YHV, TSV, MBV and V.
parahaemolyticus causing EMS/AHPND
by PCR method. Tanks were randomly
allotted to one of the following 5
treatments:

Figure 2. Cummulative mortality after 30ppt salinity challenge. All
Searup treatments showed similar improvements against the control
(P <0.05).

•
Searup 5d: Searup application
(0.1%) during 5 consecutive days from
PL5 to PL10 – EMS challenge
•
Searup 7d: Searup application
(0.1%) during 7 consecutive days from
PL5 to PL12 - EMS challenge
Searup was coated onto the diets with
water, after which the diets were
allowed to air-dry prior to feeding. At
stage PL25, each tank was allotted to 30L
tanks with an average stocking density of
500pcs/tank. Shrimp were then
submitted to an immersion challenge
with EMS causing bacteria (Vibrio
parahaemolyticus). There were 4
replicates per treatment. PL mortalities
were recorded daily over a 15-day
period.

Results
In the positive control group, first
mortalities were recorded 9h after the
EMS challenge. In the Searup treated
groups, first mortalities were recorded
24h after the challenge test. A dose
dependent effect was observed, with 5
and 7-day administrations showing the
best survival rates after challenge
(P<0.05).
EMS has a major impact in the shrimp
industry worldwide. Using Searup, which
contains immunomodulating algal
polysaccharides (MSPIMMUNITY), has shown
in this trial to be an effective product to

Figure 4. Survival rate post EMS-challenge.

improve survival rates after a challenge
with EMS causing bacteria, even when
the challenge takes place two weeks
after the last Searup application. Searup
has a long lasting protective effect.

Conclusion
The use of MSPIMMUNITY was able to
support the natural defenses of the
shrimp. This suggests that specific algae
extracts are promising candidates to help
farms achieve a good performance and
improving the overall health of shrimp
using natural products from the seas.

Cape Town International Convention Centre
Cape Town, South Africa
The Annual International Conference & Exposition of
World Aquaculture Society
Hosted by
Aquaculture Association of Southern Africa
Department of Agriculture, Forestry and Fisheries,
Republic of South Africa
Associate Sponsors
Aquaculture Engineering Society
International Association of Aquaculture Economics
& Management
WorldFish

38

Effects of a phytonutrient on aquatic
species raised under commercial
conditions
By Josselin le Cour Grandmaison, Product Manager – XTRACT® range, Pancosma SA, Switzerland
Tilapia and shrimp farming are currently
booming: Food and Agriculture Organization predicts that 12 million tons of
tilapia feed will be produced by 2020.
Shrimp farming is following the same
dynamic from 2001 to 2014 shrimp
aquaculture production has been
multiplied by 13.
These sharp rises are not without
consequences and numerous challenges
have to be overcome by industry and
farmers. Enhancement of growth
performance and improvement of the
animal health status are currently the
two main issues for these aquatic
species.
As a matter of fact, intestinal health,
integrity and functioning are key
elements in animal production and
aquaculture. Physiological research has
demonstrated that digestive tract is not
only a place where digestion is occurring,
but other systems as important as
immune defenses are also taking a
crucial place.
Some products are able to increase
digestive secretions, protect gut
epithelium and possess immune

modulating properties. However their
effects are often tested in vitro or in
research-like conditions precluding their
real assessment at farm level.
The Swiss based company Pancosma, a
global leader in feed additives, has
developed concrete solutions for
aquaculture farming. XTRACT® 6930 is a
product composed of standardized
protected particles containing carefully
selected combination of bioactive
substances found naturally in aromatic
plants and spices. Focusing on a few, well
known ingredients, a set of physiological
reactions are triggered inside aquatic
species digestive tracts: boosting feed
utilization and modulating natural
defense of aquatic species.
For instance, XTRACT® allows to better
utilize feed via an enhancement of
digestive enzyme secretions, the
improvement of nutrients absorption
and a reduction of maintenance
requirements via its immune modulation
action. It also permits to better endure
external challenges without any need for
antibiotics.
New trial results demonstrating XTRACT®

positive action on tilapia and shrimp have
been set up in commercial-like conditions. We present the results in this
article.

Evaluation of XTRACT® on tilapia
growth performance
Juvenile tilapia fish with a body weight of
2.56 g were transferred to 24 tanks: 200
fish were allocated per tank. Water in
tanks was mimicking commercial
situation.
Tilapia were fed with 3 different diets:
negative control, 200 g/ton and 300 g/
ton of XTRACT®. Each treatment was
replicated eight times. The negative
control consisted of a basal diet made of
soy bean meal, fishmeal, wheat flour,
rice, blood meal and a premix. The
XTRACT® 200 g/ton and XTRACT® 300 g/
ton diets consisted in the basal diet
supplemented with of XTRACT® at 200 g/
ton and 300 g/ton respectively. XTRACT®
was previously mixed with fish oil and
top coated at 2% onto the pellets in
order to reach additive desired concentration.

Table 1: Histological evaluation of tilapia hindgut and midgut in function of two dietary
treatments.

Negative control

Tilapia fed with XTRACT®
at 200 g/ton

A dose response was noticed on tilapia
growth performance: when XTRACT®
dose was increased from 200 g/ton to
300 g/ton tilapia performance was also
improved in a linear manner.

Hindgut

These results corroborate previews
research performed on young tilapia in
Thailand in 2015. Histological observation suggested that XTRACT® supplemented at 200 g/ton had a positive effect
on absorption surface and intestinal
integrity of tilapia (see Table1). Intense
and numerous well shaped villi were
observed in compassion to control group.

Improvement of tilapia survival rate was
also noticed when XTRACT® was
supplemented at 200 g/ton and 300 g/
ton of feed (Figure 4). This lower
mortality could be explained by the
ability of XTRACT® to modulate immune
system and help aquatic animals to
endure external challenges.

40
Survival rate (%)

Negative control

XTRACT® 200
g/ton

XTRACT® 300
g/ton

Figure 4: Tilapia survival rate in function of
treatment groups

Evaluation of XTRACT® on shrimp
growth performance
Pacific white shrimps (L. vannamei) with
a body weight of 3.06 g were allocated
into 36 cages and raised during 63 days:
225 shrimps were allocated per cage.
Cages were allocated in commercial
shrimp pond.
Shrimp were fed with 3 different diets:
negative control, XTRACT® 100 g/ton and
XTRACT® 150 g/ton. Each treatment was
replicated twelve times. The negative
control consisted of a basal commercial
shrimp diet with 35% of Crude Protein.
The XTRACT® 100 g/ton and XTRACT®
150 g/ton diets consisted in the basal
diet supplemented with of XTRACT® at
100 g/ton and 150 g/ton respectively.
XTRACT® was added directly in to feed
Final shrimp biomass (g/cage)

Negative
control

XTRACT® 100
g/ton

XTRACT® 150
g/ton

via the premix.

Discussion and Conclusion

Cages containing shrimps fed with diets
supplemented with XTRACT® displayed
higher final biomass and higher feed
intake. When XTRACT® was supplemented at 150 g/ton of feed, large improvement of shrimp Feed Conversion Ratio
was observed (-4.8%).

Dietary supplementation of this
phytogenic feed additive successfully
improves performance of juvenile tilapia
and pacific white shrimps. For these two
aquatic species final body weight, feed
intake, economic feed conversion ratio
and survival rate were improved. Using
comparative physiology it is possible to
get insights of the product’s true mode of
action (Bravo. 2015).

More importantly, shrimp fed with
XTRACT® had a strongly higher survival
rate in comparison with shrimp fed
negative control diet. Again this better
shrimp survival rate can be explained by
Shrimp survival rate (%)

Negative control

XTRACT® 100 g/ton

XTRACT® 150 g/ton

Figure 8: Shrimp survival rate in function of
treatment groups

the ability of XTRACT® to help aquatic
species to support external challenges
and stresses.

Trials at experimental farm in Vietnam
aquaculture stakeholders.
In addition to phytonutrients, Pancosma
has designed additional feed additives
based on their expertise. This portfolio
for aquatic species includes organic trace
minerals and health enhancers.

Thus the phytonutrient
answers one of the main
demands of industrials and
farmers regarding tilapia and
shrimp farming: better feed
utilization and resistance to
external challenges and
stresses. This solution has the
potential to generate greater
financial profit to aquaculture
stakeholders.

Inulin, a promising prebiotic
in the prevention of diseases in
modern aquaculture

Introduction
Application of prebiotics is a common
practice in functional feeds for fish
farming today to improve fish or shrimp
health status, promote gut integrity and
improve sustainable productive animal
performance in general. The most recent
definition describes prebiotics as follows

(Gibson , 2010): â&#x20AC;&#x153;A dietary prebiotic is a
selectively fermented ingredient that
results in specific changes in the
composition and/or activity of the
gastrointestinal microbiota, thus
conferring benefit(s) upon host health.â&#x20AC;?
Typically prebiotics resist gastric acidity
and are not hydrolyzed by digestive
enzymes nor absorbed in the digestive

system. Prebiotics are fermented by the
intestinal microbial community and
selectively stimulate the growth and/or
activity of intestinal favorable bacteria
that are associated with health (Gibson,
2010; Robertfroid, 2010). Hoseinifar
(2015) published a comprehensive
overview on the role of the most studied
and applied prebiotics and the fish

43
immune response. Mannanoligosacharides (MOS), derived from yeast cell walls
are probably the most evaluated in fish.
Oligofructose (or fructooligosaccharides,
FOS) and inulin, both β-D-fructans
differing in their degree of polymerization, have also been tested extensively.
Next to these there are plenty of
candidate ingredients with potentially
prebiotic properties in fish such as
galactooligosaccharides (GOS),
arabinoxylanoligosaccharides (AXOS),
etc. Next to the specific proven prebiotic
ingredients there are several yeast
extracts in the market as commercial
prebiotics.

Inulin and oligofructose as
prebiotics in aquaculture species
Beneo is a producer of inulin and
oligofructose, soluble indigestible
polysaccharides consisting of β(2,1)
bonded fructosyl molecules derived from
chicory root. Inulin is already successfully
used in food and feed applications.
Whereas oligofructose is fermented in
the midgut, inulin reaches the hindgut.
Inulin and oligofructose are selectively
fermented and induce a shift in microbial
composition. Addition to feed stimulates
selectively the growth of “friendly
bacteria” as illustrated in the study of
Mahious (2006) in weaning turbot in

which an increase from 0% to 14% of
Bacillus was observed after feeding of
oligofructose. A higher bacterial diversity
as well as positive effects on growth have
been observed as well.
Changes in intestinal microbiota after
addition of inulin, oligofructose or shortchain fructooligosaccharides (scFOS)
were also observed in Pacific white
shrimp (Li, 2007), Stellate sturgeon
(Akrami, 2013) and rainbow trout (Ortiz,
2013). The short-chain fatty acids (SCFA)
produced by the microbiota after
fermentation of chicory root fiber lead to
a stimulation of the villi growth. The
associated reduction of the pH in the gut

Fig. 1: Effect of dietary oligofructose as prebiotic for weaning turbot on microbiota composition (data taken from Mahious, 2006).

Figure 2: Production levels and relative amounts of SCFA during in vitro fermentation of inulin (IN) and oligofructose (OF) (internal research,
unpublished results).

44

Fig. 3: In vitro reduction of intestinal pH due to fermentation of inulin
and oligofructose (internal research, unpublished results).

creates a less favorable environment for
pathogens. Investigations by Beneo on in
vitro fermentation of prebiotics in
sturgeon showed an increased production of SCFA and a shift towards higher
butyrate production (unpublished
results).

In the trial the shift in SCFA lead to a
reduced pH in the intestinal tract as
illustrated in the below graph.
Prebiotics sometimes referred to as
â&#x20AC;&#x153;immunosaccharidesâ&#x20AC;? exert a direct
stimulating effect on the innate immune

systems (Akhter, 2015). In Caspian roach
fry Soleimani (2012) discovered a doseresponse effect on total serum immunoglobulin levels when fed different levels
of oligofructose. The results are
illustrated in figure 4.

45
Inulin in diets for Atlantic salmon
smolts (internal research,
unpublished results).
In the remaining part of this article a
promising challenge study on the effect
of inulin on productive performance, gut
health and immune response in Atlantic
salmon is presented.
Atlantic salmon smolts of 71 grams
average weight were fed during 60 days
a control diet or test diets containing two
different levels of inulin (0.2% and 0.5%).
After 60 days growth performance and
villi heights were compared. The
remaining fish were challenged with
different dosages of Piscirickettsia
salmonis after which fish mortality was
monitored during 30 days post challenge.

Results
After 60 days the growth of the tested
groups was not significantly different
however the specific growth rate (SGR)
was highest in the 0.5% inulin group and
higher in all the inulin fed groups
compared to the control group. The most
favorable feed conversion ratio (FCR) was
observed in the 0.2% and 0.5% inulin
groups.
Table 1: Growth performance of Atlantic
salmon smolts after 60 days feeding with
different levels.

Histological evaluation revealed a
marked increase of the intestinal villi
height in the inulin fed animals after 60
days as illustrated in figure 5.
The accumulated mortality 30 days after
the challenge with Piscirickettsia
salmonis is illustrated in figure 6. It
ranged from 55.6% in the control group

to 43.8% in the 0.2% inulin fed group and
32.5% in the 0.5% inulin fed animals.

Conclusion
From the presented study it may be
concluded that addition of chicory
derived prebiotics in casu addition of

46
0.2% and especially 0.5% inulin to feeds
of Atlantic salmon smolts, results in a
better intestinal health, an improvement
in productive performance and a higher
resistance to infectious diseases in this
case Piscirickettsia salmonis.

Based on internal Beneo research and
published literature, the addition of
prebiotic inulin and oligofructose in
aquafeed is an excellent solution to
contribute to fish farmers’ profitability by
improving the health condition of the
farmed fish and productive performance.
Beneo-Animal nutrition is dedicated to a
more sustainable aquaculture industry by
offering scientifically proven innovative
nutritional concepts.

Dry grape extracts authorized as
feed additives and for their use in
aquaculture
A few weeks ago, the Dry Grape
Extract (Nor-Grape® 80)
developed and commercialized

by Nor-Feed, became the first
botanical sensory additive
authorized for animal nutrition by
the European Commission.

The Dry Grape Extract is rich and standardized in total
polyphenols, procyanidins and anthocyanins, active molecules
well known for their strong antioxidant potential. It is used in
many countries to fight against oxidative stress which is the
disbalance of the equilibrium state between antioxidants and
free radicals in favor of the latter. This phenomenon can be
caused by many factors (water temperature, water quality,
level of dissolved oxygen, stress…) and may have dramatic
effects on the fish growth, health and the quality of its
products. Its potential applications in aquaculture are
numerous. In particular, grape polyphenols have been shown to
have a protective effect on fish meat when added directly on it
after slaughter (Pazos et al. 2005, Gai et al. 2015, Magsood et
al. 2013).
A trial was set up in an experimental station in the south of
France (CREUFOP, Montpellier) on sea bass (Dicentrarchus
labrax) to establish if such a protective effect would be
observed on the meat when orally supplementing the fish (drip

loss, during storage and cooking, or oxidation state) and
whether it would at the same time benefit the fish by improving
its antioxidant defenses.
120 170-gram sea bass were divided in two homogeneous
groups: a control group (“CTL”), fed a classic grower extruded
feed (43% proteins, 20% fats), and a Dry Grape Extract group
(“NG”), fed the same feed supplemented with 40ppm of
Nor-Grape®80. The fish were fed for 66 days, until slaughter,
when blood samples were taken and fish were fileted. Total
glutathione peroxidase was measured on blood samples. 30
filets per group were kept at +4°C and individually weighed at
D1 and D10. Moreover, 16 other filets were weighed before
and after being cooked for 12 min at 80°C to evaluate drip loss.
Finally, oxidized fats (TBARS) were analyzed on D10 on 5 filets
per group.
The measure of total glutathione peroxidase on blood samples
evidenced a significantly higher level (p<0,05) in sea bass

48
supplemented with the Dry Grape Extract (see figure 1),
demonstrating a beneficial effect of the grape extract on the
stimulation of endogenous antioxidant defenses.
Moreover, this improvement of the fish defenses resulted in a
less oxidized meat (see figure 2) and a reduced drip loss during
storage in the supplemented group (NG: 4,93% vs. CTL : 5,15%).
Furthermore, the improvement of the oxidative stability of the

Registering the Dry Grape Extract
A long and rigorous process
The authorization process began in 2004, when Nor-Feed
declared the Dry Grape Extract (DGE) in the European
Register of Additives to maintain Nor-Grape 80â&#x20AC;&#x2122;s right of
sale. In 2010, following a request from the European
Union, the company filed the EFSA (European Food Safety
Authority) Registration. Then, between 2014 and 2016,
Nor-Feed exchanged information with the EFSA, the
EURL (European Union Reference Laboratory) and the
European Commission on the DGE safety and efficacy and
the analysis and characterization of its active substances
(total polyphenols, proanthocyanidins and anthocyanins).
In March 2016, the EURL proceeded to an evaluation of
Nor-Feed methods of analysis, and in June 2016, the
European Food Safety Authority Scientific Committees
published a positive opinion on the DGE.

During a regulatory session, on 14th and 15th November
2016, the authorization of the Dry Grape Extract dossier
submitted by Nor-Feed was voted unanimously by the
Plants Committee of the Animal Nutrition & Veterinary
Medicines (ANVM), and published in the official journal of
February, 22nd 2017.
Fig, 1. Blood GPx levels of sea bass.

Fig. 2. State of lipid oxidation in sea bass filets.

EFSA had stressed the efficacy and safety of the use of dry
grape extract in animal feed. This decision is important in
two ways: "The presence of the dry grape extract on the
official European Union Register is for us - and our customers - the guarantee that our product is duly standardized
and based on sound and validated scientific bases.", said
Alexia Lepont, Head of Nor-Feed Quality and Regulatory
Affairs. "To our knowledge, there is no other product based
on grape extract currently being evaluated by EFSA", she
added. Moreover, since the authorization was based on
the results provided by Nor-Feed, it is the company
methods of analysis and characterization of active
substances (total polyphenols, proanthocyanidins, and
anthocyanins) that will be used for the evaluation of
possible future grape extracts looking for the same
authorization.
Many actors of the Animal Health & Nutrition industry
are already using Nor-Grape 80 to "compensate for
oxidative stress in animal farming" and "to bring watersoluble biological antioxidants", using Nor-Feed
publications to build their own allegation dossier.

49
The supplementation of the diet with 40ppm of Nor-Grape® 80
for 2 months before slaughter therefore increased the fish
antioxidant defenses. This resulted in an improved meat quality
by improving the oxidative stability of the meat leading to a
reduction of drip loss during the cooking process.
Other studies on the use of Dry Grape Extract in aquaculture
have demonstrated similar improvements on the products’
quality (meat, eggs) as well as growth performances improvement in several species (fish and crustaceans). This demonstrates the need for a combination of synergistic water- and fatsoluble antioxidants in aquaculture to better protect fish
against oxidative stress.
AFΩ

More information
References available on request.
Fig.3. Drip loss of sea bass filets during the cooking process.

filets in the NG group resulted in a significant reduction of drip
loss during cooking (-25%, p<0,01, see figure 3).

A flexible approach to optimizing the
DHA levels of hatchery Artemia
R&D

Although Artemia nauplii are widely used in the hatchery
rearing of marine fish larvae, by themselves they do not
contain a lot of the nutrition that is essential to young fish
development. In particular, they are lacking in the highly
unsaturated fatty acids (HUFAs) – docosahexaenoic acid
(DHA) and eicosapentaenoic acid (EPA) – that are essential
to marine fish growth and development. Therefore, to
increase the DHA and EPA content, hatcheries typically
subject Artemia to an enrichment phase before it is fed to
fish, whereby it is placed in an enrichment suspension that
it will proceed to ingest and incorporate into its biomass.
There are, though, two fundamental problems associated

with this standard practice model, explains Eamonn
O’Brien, Product Manager for Skretting Marine Hatchery
Feeds (MHF).
Firstly, not all Artemia are the same – as
a live animal, there are significant
disparities between its different strains
and their ability to incorporate enrichment as well as variances in quality and
strength from year-to-year, which is
termed as ‘enrichment kinetics’. And yet
the aquaculture industry has a strong
tendency to overlook these inconsistencies and look at Artemia as a constant
standard.

Secondly, there is the added complexity
that the metabolism of Artemia will very
efficiently break down the essential DHA
into other fatty acids, in particular EPA,
thereby depriving the marine larvae of
their very high DHA requirement.
“Hatcheries typically want a DHA-EPA
ratio of 2:1 in their Artemia, which can
often be difficult to achieve because of
this inherent ability,” says O’Brien.

To mitigate these and other constraints
associated with Artemia, a number of
hatchery operations have replaced it
with a formulated diet. But recognising
that Artemia substitution is not an option
for every marine hatchery and that it is
important that the many hatcheries that
continue to follow this protocol make
their Artemia as nutritionally rich as
possible, Skretting MHF has invested
considerable R&D into the delivery of a
feed expressly focused on optimising the
level of DHA in the live feed.
The result is its ORI-N3 Artemia enrichment, which delivers a highly efficient
incorporation of DHA into the live feed
while also providing far greater flexibility
in this essential marine hatchery process
compared to standard enrichment
protocols.
Developed at MHF’s Centre of Excellence
in Vervins, France, ORI-N3 is an algaebased liquid that is aligned with its other
ORI range concepts in that it is designed
to be ingested by the animals more
efficiently than traditional methods, as
well as being easy to use – it is supplied
in 2kg foil stand-up spout bags. The
dosage is simply weighed, mixed with
water and then administered to the
Artemia tank.
Because it is algal-based there are no
superfluous oils, while the risk of oxygen

52
level challenges are much less likely than
with standard enrichments. The Artemia
also maintain a good protein base. A
direct outcome of these benefits is a
greatly reduced mortality rate and a
much cleaner enrichment.

Flexibility
“It was also very important to provide a
solution that is adaptable to each
hatchery’s specific requirements, rather
than just a single general application
protocol,” says O’Brien. “All hatcheries
are different; each has individual needs
and motivations, so it is vital that the
products made available to them are
sufficiently flexible to fulfil those aims.”
Based on what hatchery managers want
to achieve with their Artemia as well as
what best suits the operations within
their facility, ORI-N3 offers everything

between 12- and 24-hour enrichment.
If a medium level n-3 HUFA content and
highest DHA-EPA ratio is the target, for
example, then a single-dose 12-hour
enrichment tends to present the best
option. Alternatively, if a hatchery is
more interested in achieving a maximum
HUFA entry, it should elect for a 24-hour
enrichment and two doses, says O’Brien.
“Because ORI-N3 establishes a much
more efficient intake of DHA, its
application can be as low as 400 ppm
and still providing very good incorporation into the Artemia and an excellent
DHA:EPA ratio. Such low dose application
also assists in keeping the enrichment
clean and is of course very cost-effective.

“In addition to providing unmatched DHA
content, the flexibility and easiness-touse allows each hatchery to tailor the
product to its own specific requirements.

With commercial trials imminent, our
goal is to have the market fully up to
speed ahead of the new season, starting
in September,” says O’Brien.
AFΩ

Join us for the 10th in Aquafeed.com's
series of international technical
conferences for aquafeed industry
professionals.

Limited places
REGISTER NOW
feedconferences.com

Aquafeed Horizons conferences focus on
practical information and have become the
recognized event in the calendar for
industry stakeholders worldwide; it has

been arming delegates with the latest processing and formulation solutions to help
keep ahead of the trends and
changes in the industry since 2006.

Sponsored by:

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54

Aquafeed Horizons 2017
PROGRAM
Unravelling the mysteries of extrusion die flow using CFD

Daniel Stoffner; Bühler Nutrition, Product
Management Aqua Feed & Pet Food,
Switzerland
Today, with the power available in standard
computer workstations it is possible to
realistically model the flow through
elaborate extrusion dies, even in an
industrial R&D environment, in particular,
the effects of viscous heating and shear-thinning viscosity on
aquafeed die flow. Typical models spanned the final windings of
a twin-screw, the transition from a twin-screw barrel to an
axisymmetric die, as well as inserts and nozzles. However, more
complicated aspects such as heterogeneous material, viscoelasticity, thixotropic viscosity or gas expansion have not been
addressed.

Thomas Ellegaard Mohr, Segment Manager/
Sales Application Manager, ANDRITZ Feed &
Biofuel, Denmark
Industrially produced feed is undergoing a
continuous quality improvement process.
The different types of feed are subject to
different demands, the feed/food’s
functionality. e.g. on fish farms in terms of
floatability or sink ability and pellet durability to assist
mechanical handling without the generation of fines. Increased
demand for feed also influences the availability of "classic" raw
material, this gives new challenges to ensure that the extrusion
technologies and process control are developed to adapt
accordingly.

New developments in aquafeed production by extrusion

Joe Kearns, Vice President Aquafeed Division,
Wenger Manufacturing Inc., USA
Aquafeed production methods continue to
advance in order to keep pace with changes
and requirements desired by the industry.
High capacity sinking and floating feed
machines are now capable of making
products as small as 0.5 mm with production
rates measured in tons per hour. AquaFlex designs are
available for making a complete, wide range of all styles of
aquatic feed. There are density control packages for instantaneous corrections of density while running as well as computer
and In-Line measuring devices, all controlled automatically for
speed and accuracy avoiding costly rework and improving
efficiency by reduced down time and higher plant yield.
Capacity increases in large single screw extruder's also improve
cost efficiencies by producing higher capacities per hour. Dryer
improvements also reflect the industries desire to improve
efficiency in production of predicable results.

Alternatives to water-plasticization in the extrusion process –
reduced drying costs and improved physical pellet quality
Rafiq Ahmad, Industrial PhD candidate,
Cargill Aqua Nutrition, USA
Possible plasticizer candidates such as free
amino acids and pH have been evaluated
combined with moisture in a soy protein
concentrate model system. The study
demonstrates that free amino acids and low
molecular weight water-soluble peptides can
replace moisture as a plasticizer in the extrusion process. Due
to the need for higher moisture level during extrusion processing of plant-based diets these require more energy for
drying compared to fishmeal based diets. The use of protein

55
based plasticizers opens up the possibility to obtain a satisfactory â&#x20AC;&#x153;cookâ&#x20AC;? at reduced moisture level with a potential for
significant reduction of the energy consumption. The results
from this study documents the possibility to develop a new
processing add for the fish feed industry serving multiple
purposes as nutrient, plasticizer and binder in extruded fish
feed.

system to conserve energy and improve efficiency. Water can
also be condensed and reintroduced back into a preconditioner or extruder, reducing the volume of fresh water
needed for the process and eliminating effluent concerns from
a heat recovery system and a processor can raise discharge
moisture and get more out of the production line with no
additional cost or additional dry ingredients. The value of this
recaptured production can be surprising.

Processing efficiencies for sustainability and profits
Scott Vallette, Market Manager, Buhler
Aeroglide, U.K.
This presentation will introduce three
opportunities for processing efficiencies in
drying that can ensure sustainability and
improve bottom line profits: if fines are
continuously collected in the dryer, they can
be carefully reintroduced upstream to
eliminate waste, product loss and the need to introduce
additional raw material for the same output. Removing the
fines from the dryer on a continuous basis can also reduce the
cost and time required for cleaning and reduce potential fire
risks; heat can be captured and reused with a heat recovery

Hybrid dryer exhaust air processing; towards a sustainable
solution for odor abatement with concurrent energy- and
water recovery
Anders F. Haubjerg, Sr. Process Engineer,
Graintec A/S, Denmark
Integrating the goals of reducing odor,
recovering energy and reusing condensed
water back into the process, in a single endpipe drying solution has been the subject of
a recent collaborative development project.
A technical-economical comparison with conventional odor
abatement technologies will be given, alongside results from
pilot-scale experimental stages: condensation based odor

56
abatement efficiency, energy recovery potential and feeding
trials using feed produced with recycled water, condensed from
the drying process. This new solution brings a promising
alternative to the existing technology pool.

Feed and food processing – Technology transfer and novel
ingredients

Dr. Olav Fjeld Kraugerud, Manager, Centre
for Feed Technology (Fôrtek), NMBU,
Norway
The drive for new ingredients puts a timely
pressure on processing evolution, with
respect to both physical quality of the
pellets, and nutritional quality. The talk will
give some examples on processing of novel
ingredients, and strategies to reach the goal. E.g., the food
sector has valuable knowledge on ingredients processing, that
the feed sector can benefit largely form.

Mycotoxins in aquaculture: occurrence and impact in rainbow
trout (Oncorhynchus mykiss).
Rui Alexandre Gonçalves, Scientist Aquaculture, BIOMIN Holding GmbH, Austria
To evaluate the consequences of mycotoxin
contamination in European aquaculture
finished feeds, two experiments were
performed to study the effect of short and
long term feeding of Fusarium mycotoxins to
rainbow trout, using natural contaminated
raw materials and pure mycotoxins. Moreover the influence of
mycotoxins against Yersinia ruckeri susceptibility was evaluated.
All experimental diets revealed the presence of other mycotoxins metabolites/toxins alongside added Fusarium. The presence
of these naturally-occurring metabolites/toxins, highlights the
high risk of mycotoxin contamination in aquaculture finished
feeds within Europe. Results confirmed that the ingestion of
mycotoxins, within the levels found on finished feeds across
Europe (up to 1000ppb), can lead to an overall decline in
performance which ultimately results in economic losses.

Toward higher inclusion of soybean meal in salmon feeds
André Dumas, Director of Fish Nutrition, The
Center for Aquaculture Technologies Canada,
Canada
The negative effects of soybean meal on
Atlantic salmon reported in the literature are
variable. Growth of Atlantic salmon is not
always negatively impacted by diets
containing relatively high levels of soybean
meal. Moreover, the inducement of enteritis differed between
soybean sources and we have demonstrated that soybean
tolerance/utilization in this species is also influenced by
genetics in a recent study. This presentation will address and
explain further these discrepancies to ensure soybean meal is
used increasingly in an optimal manner in Atlantic salmon
feeds.

Effect of an immuno-modulating algal extract on disease
prevention in aquaculture
Maarten Jay van Schoonhoven, Aqua Care
Manager, Olmix SA, France
Nutritional studies have shown that green,
brown and red seaweeds possess good
nutritional characteristics, and in addition,
also have biological active compounds
including proteins, polyunsaturated fatty
acids, pigments, polyphenols, minerals,
vitamins and polysaccharides. Biological activities related to
these compounds include: antiviral antibacterial, antitumor,
anti-proliferative and immunomodulatory activities. Studies in
collaboration with INRA have demonstrated high immunemodulating activities. More recently University trials where
shrimp were challenged with Vibrio parahaemolyticus bacteria
causing EMS, showed long lasting effects that helped improving
survival rates. Since these University trials, field trials in both
fish and shrimp have confirmed the beneficial effects of these
sulphated polysaccharides from marine algae.

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Breaking the bottleneck: Feed-based solutions to the recurring
challenges in aquaculture

Deforestation-free and sustainable vegetable fats and proteins
for aquaculture feed

Kabir Chowdhury, Global Product Manager Aquaculture, Jefo Nutrition Inc., Canada
Despite the significant growth in the share of
three major commercially farmed species tilapia, shrimp and salmonids, issues such as
poor consumer perception due to the lack of
social responsibility, leadership and poor
governance, and as well as environmental pollution and
frequent outbreaks of old and new diseases remain major
hindrances. These issues have been creating a bottleneck for
the sustainable growth of the industry. The major contributing
factors, which can be partially solved through dietary means,
are mainly environmental and health issues. Reducing waste
output for better environment, and ensuing better performance
and immune response are possible through various dietary
means such as better formulation and using various in-feed
additive based solutions. This presentation will discuss recurring
and upcoming issues that the industry is facing and highlights
some of the commercially available feed-based solutions.

Dr. Norbert Schmitz, Managing Director,
ISCC, Germany
The use of protein and fats sources of
vegetable origin have potential negative
effects on the environment, as most of the
fishmeal alternatives are cultivated in highly
bio-diverse tropical and equatorial regions
and could derive from unsustainable deforestation practices.
This presentation discusses an innovative system based on
remote sensing data (Global Risk Assessment Services), able to
verify whether unsustainable production practices are used for
the production of raw materials in aquaculture feed. The
system allows the identification of agricultural land obtained
through deforestation. In addition, the several stages of the
feedstock preparation and processing can be mapped, offering
a complete traceability of the supply chain of the feed products.
Cases based on soybean meal and palm oil production are
presented in this contribution.

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FVG Select Opening Hours

FVG Select—the networking event
Aquafeed Horizons is routinely held alongside Victam International’s tradeshows,
FIAAP/Victam/Grapas (FVG) that take place in Cologne every three years and
Bangkok every other year. This year is a ‘gap year’ – and Victam International has
taken the opportunity to fill it with a new event, called FVG Select. It is a two-day,
conference-led networking event, which will take place on June 13 and 14, 2017
and which will have an exhibition by a select group of 55 companies.
Aquafeed Horizons is one of six independent conferences taking place during the
event.
A highlight of FVG Select will be a business matchmaking program. It will be done
through an easy-to-use technology platform combined with a personalized service
to help maximize your networking opportunities. A network reception will be held
on Tuesday, June 13th from 17:00 - 19:00 giving exhibitors, delegates and visitors
the opportunity to relax, socialize and network.

Soy Aquaculture Alliance â&#x20AC;&#x201C; Aquaculture America:
teaming up to forge a successful future for
U.S. aquaculture
The Soy Aquaculture Alliance (SAA) Annual Coalition Meeting, held during the Aquaculture
America Conference, featured speakers with a wide range of experiences and expertise who
shared exciting updates on work underway to support the U.S. Aquaculture Community
By Bridget Owen, Executive Director, Soy Aquaculture Alliance, USA
The Soy Aquaculture Alliance (SAA)
recently held the 13th Annual Coalition
Meeting during the Aquaculture America
Conference. The annual event includes
speakers with a wide range of aquaculture experiences and expertise who

share exciting updates on work underway to support the U.S. Aquaculture
Community. This year proved to be
another full slate of exciting updates and
discussion topics.
Nermeen Youssef Abass, 2017 U.S.
Aquaculture Society and Soy Aquaculture
Alliance Student Travel Award recipient,
began the meeting with a presentation
on her current research work at Auburn
University working with channel catfish.
SAA is honored to work with U.S.
Aquaculture Society to support this
important award. U.S. Aquaculture
benefits greatly from the high quality
research conducted in our nation and the
great educational programs that develop
high quality students to support U.S.
Aquaculture well into our future.
Research remains of key importance to
aquaculture and to helping continue to
grow in smart and efficient ways. The
United Soybean Board and many State

Photo: Scott Bauer, USDA-ARS

Soybean Organizations support the Soy
Aquaculture Allianceâ&#x20AC;&#x2122;s Soy in Aquaculture
Research Program. Researchers
currently working on research in this
program presented updated on their
work, including Dr. Tiago Hori from the
Center for Aquaculture Technologies and
the work they have been doing with SAA
to Identify Genetic Markers Associated
with Growth Performance on a Soybean
Meal Based Diet for Atlantic salmon. Dr.
Jesse Chappell, Auburn University,
shared the work he and Dr. Terry Hanson
have underway with In Pond Raceway
Systems (IPRS) development including
the rapid adoption of this production
system in China and introduction of the
system elsewhere in the world.
Dr. Guillaume Salze also shared the work
he and his team from Auburn University
worked on regarding the Effect of Pellet
Size, Extrusion Technology, and Water
Temperature on Taurine Leaching in SoyBased Fish Feeds. This year we had an

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Photo: United Soybean Board

important announcement to make. Dr.
Salze announced the very recent news of
following years of research, the
Association of American Feed Control
Officials (AAFCO) has approved a new
definition for the use of taurine in fish
feeds. Taurine is an important amino acid
for fish, but it was not approved for use
in aquafeeds produced in the United
States – until now. “This had left feed
formulators in the United States with
little choice but to provide taurine
through an animal-based ingredient,
typically fishmeal” said Guillaume Salze,
the research associate at Auburn
University’s School of Fisheries Aquaculture and Aquatic Sciences who spearheaded the project.
“Being allowed to add crystal taurine to
fish feeds means that feeds can be
formulated with less fishmeal and more
plant proteins (such as soy), thereby
reducing costs and improving sustainability at the same time” Salze added. The
new definition includes all life stages in
all fish species. Multiple groups collabo-

rated on this project, including universities, federal agencies, and non-profit
organizations, and funding sources. This
was a major research effort supported by
SAA members, the United Soybean
Board, National Oceanic and Atmospheric Administration (NOAA) and United
States Department of Agriculture (USDA)
partners that began a few years ago.
Advanced Soy Proteins are important
resources for aquafeeds and SAA
Members Prairie AquaTech (ME-PRO®),
the Ohio Soybean Council (Enzomeal)
and Midwest Ag Enterprises (NutriVance)
discussed their advanced soy protein
products and work that was underway in
this sector. Pentair shared an update
on their work and an innovative, virtual
tour of their facility at PAES W.A.T.E.R.
and Insta-Pro shared information on
their aquafeed production equipment
and on the work they do with extrusion
equipment. The aquaculture industry
relies on great partners in feed ingredient innovation and in equipment
innovation.

“Being allowed to add
crystal taurine to fish feeds
means that feeds can be
formulated with less
fishmeal and more plant
proteins (such as soy),
thereby reducing costs and
improving sustainability at

the same time”

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Aquaculture in the United States also has
critical partners in the U.S. Government
Agencies and Departments. SAA was
honored to have Dr. Gene Kim from
USDA National Institute of Food and
Agriculture provide an update on their
work with aquaculture and insights on a
new effort underway on an Innovation
Challenge to explore new approaches to
increasing the consumption of U.S.
Aquaculture production domestically.
Dr. Caird Rexroad III provided an update
on USDA Agricultural Research Service
Aquaculture priorities and research
programs. Dr. Michael Rubino, Director
of the Office of Aquaculture at NOAA's
Fisheries Service, shared with the group
an update on work in the offshore efforts
including new discussions for the
Western Pacific and NOAA programs
working at creating models utilized in
exploring siting opportunities in the
offshore environment.

“Offshore Aquaculture remains
an important opportunity for
U.S. Aquaculture to grow and
to supply high quality marine
products for our consumers”
Offshore Aquaculture remains an
important opportunity for U.S. Aquaculture to grow and to supply high quality
marine products for our consumers. Don
Kent from Hubbs Sea-World Research
Institute provided a presentation
updating the audience on their work in
establishing a farm off the Coast of San
Diego, California. Their work continues
in the permitting process. Significant
challenges remain in the area of
permitting for aquaculture and are a key
area for all of us in the U.S. Aquaculture

Community to focus on collaboration for
solutions.

Photo: NOAA National Ocean Service

SAA shared updates on the sustainability
of U.S. Soybean Production and the U.S.
Soybean Sustainability Assurance
Protocol. We also updated the audience
on the work of the Coalition for U.S.
Seafood Production (CUSP) and the
efforts underway in this coalition to
educate and advocate for the growth of
U.S. Aquaculture.
The final speaker was a new participant
to Aquaculture America and proved the
importance of collaboration. Harlon
Pearce with the Gulf Seafood Institute
(GSI) shared with the work GSI has
underway to support aquaculture in the
Gulf of Mexico. GSI is approaching this
work in an innovative and successful way
through building important partnerships
and sharing important outreach on the
value aquaculture can bring to the
region.
It takes a team for us to achieve greater
success for U.S. aquaculture and this
meeting highlighted the importance of all
the work underway to support our U.S.
aquaculture community
as we grow and thrive.
AFΩ